Accessing and Reading Diagnostic Trouble Codes

The CCR diagnostic systems may be actuated by either of two methods. Grounding the diagnostic enable circuit at pin "C of the Data Link Connector (DLC) or by using the control module wiring harness connector. To read codes using the control module connector, ground pin D2 to pin D16.

The 3 driver select switch LEDs will blink in unison to transmit blink code diagnostics. Error diagnostic trouble codes can be read by counting the number of flashes of the LED's. The error diagnostic trouble code display will start after pin D2 has been grounded for three seconds before beginning the blink diagnostic trouble code sequence. The sequence starts with a three second LED off period. Then diagnostic trouble code 12 is displayed three times to mark the beginning of the sequence. Next, each stored code is blinked out in ascending order. Each diagnostic trouble code is displayed three times before proceeding to the next diagnostic trouble code. If pins D2 and D16 remain connected, the entire diagnostic trouble code sequence will repeat beginning with diagnostic trouble code 12 flashing three times.